The present disclosure relates to a semiconductor storage device and system, and more particularly, to a semiconductor storage device and system in which a read voltage level is compensated.
In semiconductor storage systems, a read voltage level for reading data varies due to deterioration of oxide layers, a charge loss mechanism, variation in ambient temperature, or the like caused as the semiconductor systems are used. When the read voltage level is varied, and if data is read at an initially set read voltage level, it is often the case that the data is not correctable using error correcting codes (ECC). Accordingly, a method of measuring how much the read voltage level is varied compared to the initial read voltage level may be used. In this case, the frequency of reading should be minimized to prevent a decrease in read speed.